1. Field of the Invention
The present invention relates generally to computer graphics/animation/scene generation applications, and in particular, to a method, apparatus, and article of manufacture for selecting objects in a scene.
2. Description of the Related Art
Directors and layout artists use the camera as the main point of view for any shot or set of shots. This view is dependent upon many different factors, including a determination of the object of a story or what is important for the user to see, which may or may not be occluded during a particular sequence.
There may be times when a director or layout artists will need to select an object that is partially or completely occluded by a semi-transparent object. Similar to selection via an alpha matte (100%) transparent, the user is often constrained to the view from the director's camera.
To select/view an object in the prior art, a user is required to alter an entire scene in one of two ways:
(1) Changing to a different viewport or camera, performing some operation and then returning back to the main camera point of view. Such a process is error prone and time consuming.
(2) Selecting an object, hiding the object, and then repeating the selecting and hiding until the user gets to the object they want, followed by unhiding all of the objects.
Both of the above processes would need to be repeated if the desired effect was not obtained.
In other words, when working in a three-dimensional (3D) environment, layout artists must be able to select objects that are not visible (e.g., may be occluded/hidden behind other objects) in a quick and efficient manner. As a further constraint, the layout artist may be constrained (e.g., by a director) such that the camera cannot be moved around. As an example, if a layout artist is standing in the middle of a jungle scene, the director may request that the layout artist, while remaining in the current vantage point, remove the 10th fern (behind other ferns) in the scene. The layout artist/user is required to somehow find out where the fern is located (within the scene), select the fern, and remove the fern. In the prior art, the user had a list of all objects in the scene, and was required to blindly/randomly select various objects (e.g., ferns) until the user was in the correct area of the scene and had selected the correct object. Such a prior art process is slow, inefficient, and prone to error.
In view of the above, what is needed is the ability to easily select an object that may be partially or completely occluded without having to perform multiple operations and altering/changing an entire scene.